Lawyers for Colm Murphy have begun an appeal against his Omagh bombing conviction.

Murphy, 51, is serving a 14-year sentence for conspiring to cause explosions that killed 29 people in August 1998. He is the only person convicted in the case.

However, his lawyers have launched 45 grounds of appeal, some based on the fact that two garda detectives were found to have falsified interview notes.

Colm Murphy arrived from prison amid tight security for the appeal hearing that is expected to last at least three days.

He was found to have provided two mobile phones used by the bombers who carried out the Omagh attack. This finding was backed up by verbal admissions to gardaí and by mobile phone records.

However, Michael O'Higgins SC said ESDA tests revealed that a garda interrogation team rewrote its interview notes after realising it had inserted a false statement concerning Murphy's wife.

The false statement has suggested that his wife was a sister of a woman associated with a Real IRA figure.

Mr O'Higgins said the Birmingham Six and Guildford Four appeals had been won with the results of ESDA tests that proved police had lied.

He said the Special Criminal Court had dismissed the testimony of the two officers involved but failed to give any evidence to show that other officers had not been contaminated by their perjury.