Updated 18.35:

Thomas 'Slab' Murphy has been jailed for 18 months, for failing to file tax returns for his farming activities between 1996 and 2004

In December, Mr Murphy (66), who lives at Ballybinaby, Hackballscross, Co Louth, was found guilty of nine counts of tax evasion.

An investigation was launched after his farm was raided in 2006 and the court heard he has built up a tax liability of just under €190,000.

He appeared before the Special Criminal Court earlier for sentencing.

Mr Justice Paul Butler said the three-judge panel took his age and otherwise clean criminal record into account but felt he had to serve a custodial sentence.

Alleged former IRA chief Thomas 'Slab' Murphy arrives at the Special Criminal Court in Dublin where he will be sentenced today for tax evasion. Picture by: Niall Carson / PA Wire/Press Association Images

Revenue raid

In 2006, the Criminal Assets Bureau raided Thomas 'Slab' Murphy's farm and found bags of money hidden in hay bales along with computers, ledgers and over half a million euro in un-cashed cheques.

An investigation was launched into his farming activities and he was convicted on nine counts of evading tax between 1996 and 2004.

His total bill to Revenue now stands at just under €190,000, when penalties and interest are factored in.

At his sentence hearing earlier this month, Mr Murphy's barrister questioned the figures produced by the State and asked the non-jury court to consider his otherwise clean criminal record the impact a custodial sentence would have on a man approaching his 67th birthday.

The maximum penalty for tax evasion is five years in prison.

Francesca Comyn was at today's sentence hearing for the Sunday Business Post- she says a few last minute arguments were put forward by Mr Murphy's defence team: