Progress on a £31m HMRC tax avoidance case is in jeopardy after the arrest of an HMRC official on suspicion of wrongdoing.

Investment specialists Future Capital Partners were due to appeal against an earlier decision by the First Tier Tribunal (FTT) which ruled in late 2011 that two film partnerships set up by the company were not entitled to claim tax relief.

The partnerships, named Proteus and Samarkand, raised around £31m from wealthy investors which was used to purchase rights in famous films such as The Queen starring Helen Mirren. The rights were leased back to the studio, allowing investors to claim tax relief on the sale.

But the FTT ruled that the film schemes were 'not undertaken on a commercial basis and therefore not entitled to sideways tax relief'. Future Capital Partners announced at the time that it intended to appeal against this, and that appeal was due to be heard this month.

However, the company has now sent a letter to clients stating that HMRC made an emergency application to adjourn the appeal on 29 April 'following the arrest of an HMRC officer who had assisted in preparation of a witness statement'. As a result, the appeal hearing is likely to be delayed until next year.

In a statement, HMRC said: 'All allegations of improper behaviour against HMRC staff are taken very seriously and appropriate action taken. For legal reasons we cannotcomment further at this time.'

HMRC has placed more than 600 film investment schemes under inquiry in recent years as part of a move to combat perceived tax avoidance.

It has already won a FTT case against another scheme promoted by Future, called Eclipse 35, whose 289 investors included former Manchester United football manager Sir Alex Ferguson, which was claiming £117m in tax relief on a complex $1bn deal with Disney.

An appeal in this case is expected to be heard in the autumn.