Image copyright iSmay family Image caption Adrian Ismay died 11 days after he was injured when a bomb exploded under his van

A man ordered to appear as a witness in his brother's murder trial has appeared in court but refused to answer questions.

Christopher Robinson is accused of murdering prison officer Adrian Ismay.

Mr Ismay, 52, died in March 2016, 11 days after a bomb exploded under his van close to his east Belfast home.

The accused's brother Peter Robinson was due to give evidence earlier in the trial but failed to attend, citing medical reasons.

He was then told by a judge to attend or an arrest warrant would be issued.

At the time of the murder, Peter Robinson worked at a youth hostel in west Belfast and was due to answer questions about claims he disabled the CCTV system the night before the bomb exploded and told a colleague "our Christy is calling".

Image caption A bomb detonated under Adrian Ismay's van in the Cregagh area of Belfast

Prosecutors have said a red Citroen C3 containing the bomb was driven by Christopher Robinson to Mr Ismay's Hillsborough Drive home - the same make and model Peter Robinson drove to work hours before the device exploded.

Christopher Robinson, 48, from Aspen Park in Poleglass, has been charged with murdering Mr Ismay, possessing an improvised explosive device and providing money or property for the purposes of terrorism.

He has denied all of the charges against him.

Just before Peter Robinson was called to the witness box, his barrister revealed that in the aftermath of the murder his client was arrested and questioned and was therefore a suspect.

The defence barrister said that over a five-day period in March 2016, Peter Robinson was interviewed 13 times under caution.

He was re-arrested in February 2017 and on that occasion he was interviewed six times.

Image copyright Pacemaker Image caption Christopher Robinson denies killing Adrian Ismay

The barrister said Peter Robinson "refused to answer any questions other than to state his name and address" and revealed he "provided to the police a pre-prepared statement through his solicitor".

On Monday, a judge at Belfast Crown Court told the witness that if there was a question asked that ran the risk of prosecution or increased the risk of prosecution he had a right not to answer that question.

A prosecution barrister then posed a series of questions to Mr Robinson.

To the first he replied: "I am going to decline answering on the basis of not incriminating myself."

He then declined to answer further questions for the same reason.

The prosecutor said he had no further questions and said the prosecution intended to rely on the statement given to police.

The trial continues.