Jamie Bryson Twitter row: PSNI and experts respond to claims that police tried to jam mobile phones during DUP meeting

During the meeting, loyalist campaigner Jamie Bryson was apparently able to live-Tweet what Sir Jeffrey was saying.

He tweeted that the PSNI were being consulted by senior DUP HQ staff. "They are trying to use technology to sweep the room," Mr Bryson claimed.

He later claimed that Sir Jeffrey told the delegates that "efforts to block phone signals hasn’t stopped the reporting from the meeting".

However the PSNI poured cold water on the claims. A PSNI spokeswoman responded: "The Police Service of Northern Ireland has no involvement in this."

Former PSNI ACC Alan McQuillan affirmed the PSNI response.

"There is technology to do this but I cannot see any circumstances in which the PSNI would do that for a political party," he told the News Letter.

Police would require a judge's authority to block phone reception in such a manner, he said, and while it can be done, he said police would not carry out such an operation for a political party.

Former Special Branch Detective Inspector William Matchett said he did not know if the PSNI currently has such technology "but it does exist".

He has seen it working in Iraq and Afghanistan.

"The US military blocked all cell phone signals in case the name of a dead soldier was released before the authorities had informed the family," he said. "But why would the PSNI block cell phone signals for a political party, even if they had the capability? To me, that is absurd. I would be astounded if that happened. It is not a law and order issue."

Roy McComb, a former head of PSNI Organised Crime and ex-Deputy Director at the National Crime Agency agreed.

"The PSNI wouldn’t use technology to facilitate a party political meeting," he said. "Any technology that they may have would only be used for the purposes of public safety and crime prevention, properly authorised under legislation."