Judges at the Special Criminal Court trial of a Northern Irish man accused of possessing an explosive substance will deliver judgement on March 1.

Samuel Devlin (aged 55), with an address at Golf Suite, Finnstown House Hotel, Lucan, Co Dublin has pleaded not guilty to the unlawful possession of the explosive substance (PETN) at the same address on May 11, 2014.

It is the prosecution's case that Mr Devlin booked into the chalet at Finnstown House Hotel using a false name and that an explosive substance was found inside rolls of detonating cord wrapped inside a towel in a laptop case while he was residing in the room.

Today, the three-judge, non-jury court heard closing speeches from the prosecution and the defence.

Tara Burns SC, prosecuting, told the judges to reject any suggestion that exhibits found in the room at Finnstown House Hotel, including detonating cord inside a laptop bag, were there "bar through being there before gardaí searched the room".

She said that the court can be satisfied that within the detonating cord an explosive substance, PETN, was found.

An important question was whether or not Mr Devlin had possession of the explosive substance, Ms Burns said, adding that the court can be satisfied that he had a requisite degree of knowledge and control of the substance.

She said that the explosive substance was found within the laptop bag and that there was a connection between the accused and that item.

The court has evidence from fingerprint experts that Mr Devlin's fingerprints were found in the laptop within that bag, she said, as well as evidence that the accused man's DNA sample matched a swab taken from the laptop's plug.

A label marked 'explosives' was attached to the detonating cord, she said.

"There is a clear connection between the accused and these items," Ms Burns said.

She also said that there is a "clear connection" between the accused man and the room at the hotel, stating that the court has heard evidence in relation to the occupancy of the room, that it was booked in the name of Joseph Murphy and that the booking commenced on March 31st, 2014 and continued through to May 10.

Ms Burns also referred to identification documents found in the room, including a current passport and a social welfare card, "all referable to the accused man".

The judges heard of evidence of a member of the National Surveillance Unit (NSU), who previously told the court he observed Mr Devlin in the vicinity of the hotel on May 9.

Ms Burns said that during interviews with gardaí Mr Devlin failed to account for his presence in the room.

She also said that the items found in the room "cannot be looked at as innocent items, entitled to an innocent explanation".

Mr Devlin did not explain the presence of these items in the room during interviews, she said.

"If Mr Devlin did have an explanation for them, that was the time for him to explain them to the gardaí," she said.

Ms Burns also referred to evidence about a bag found in a bin outside the hotel two days before the alleged offence.

Within the bag were latex gloves and some detonating cord, which had been cut open, she said.

She told the court that there is a link between the items in the bin and the accused man, as well as between the items in the bin and the items in the room.

"This links the accused to the actual cord itself," she said.

Bernard Condon SC, for Mr Devlin, told the judges that if there is a rational explanation possible, which points to innocence, the court must adopt the explanation in favour of the accused.

He said that the prosecution must prove that Mr Devlin had knowledge and control of the explosive substance and that the prosecution had failed to prove this.

"In order to establish possession, one must establish knowledge and control," Mr Condon said.

He told the court that the prosecution must prove Mr Devlin had control over the substance, knowledge of the item, as well as knowledge of what it was.

"There was no evidence of the accused man's DNA on the detonating cord," the barrister said.

Mr Condon also submitted that the evidence of the NSU detective, who told the court he saw Mr Devlin dispose of a plastic bag in a public bin, was "entirely compromised and deeply worrying".

He asked the judges to reject the detective's evidence "from start to finish".

Mr Condon said that, during cross-examination, the detective said the bag was pale yellow.

In photos, the bag was white, the court heard.

The detective saw the bag when in the witness box, Mr Condon said, adding, "This is not just an unreliability, it is sinister."

The lawyer then told the judges that the prosecution "asks you to take a number of small portions of evidence, a blinkered snapshot, and draw an enormous conclusion from it".

He said that there is no evidence Samuel Devlin booked the hotel room or that he was Joe Murphy, that there was no obvious evidence linking him to the room.

Referring to the explosive substance, Mr Condon said, "The prosecution has failed to establish he had complete physical control over it, that he knew of its existence at all, also that he knew of its qualities."

Mr Justice Paul Butler, presiding with Judge Alison Lindsay and Judge William Hamill, remanded Mr Devlin in custody until March 1st, when judgement on the case will be delivered.