IRISH international drug trafficker Christy Kinahan faces being transferred from his Spanish prison cell to a Belgium jail this week when a court there rules on an appeal he lodged against a money-laundering conviction in 2008.

In May 2008, Kinahan received a four-year sentence in Belgium for money laundering assets worth in the region of €2.5m.

He appealed the conviction after serving a few months and was out on bail when he was arrested in Spain two weeks ago as part of a major investigation into his gang's €1bn drugs empire.

On Thursday, the court of criminal appeal in Belgium will decide to uphold or reject his appeal. If it is upheld, as is expected, his sentence will be activated and he will be transferred back to Belgium to serve his time.

The 53-year-old Dubliner is the source of most of the cocaine and cannabis that comes into Ireland and is the leader of the major international drugs and money laundering cartel under investigation across Europe.

Kinahan was one of 22 people arrested in Spain two weeks ago and was brought before the Spanish courts last weekend.

He has been remanded in custody in Spain pending further investigation. He is being detained at Malaga's Alhaurin de la Torre jail along with his two sons, Daniel and Christy Jnr, who were arrested in the same probe.

Kinahan can be held in prison without charge for two years while the Spanish authorities, the gardaí and the British Serious Organised Crime Agency continue their investigations.

His arrest is likely to lead to a major drugs shortage on the streets in the short to medium term. Gardaí involv­ed in Operation Shovel, which included police forces in Ireland, Britain and Spain, believe Kinahan organised drugs shipments with a street value of over €1bn – some sources say the final figure could be as high as €1.5bn.

Gardaí have seized €70m worth of drugs sourced by Kinahan and his gang since 2002 and estimate that the seizures amounted to only 5% to 10% of the total drugs that reached Ireland undetected.

Spanish police are planning another series of raids in the coming weeks. Crime boss 'Fat' Freddie Thompson is to be targeted. He has fled Spain and is now in Holland.