EU questions Russia over fund lawyer's death

* Commissioner concerned by failure to investigate fraud

* EU statement comes ahead of EU-Russia summit next week

BRUSSELS, May 26 (Reuters) - The European Union questioned Russian ministers on Wednesday about the death in custody of a lawyer for what was once Russia's top investment fund.

The EU home affairs commissioner raised concerns in a meeting with Russia's interior and justice ministers about Moscow's failure to investigate officials involved in a $230 million corruption scam surrounding Sergei Magnitsky's death.

A statement from Cecilia Malmstrom's office said her questions at the meeting in Kazan, Russia, focused on deprivation of medical care to Sergei Magnitsky and concealment of information about his state of health before he died.

Magnitsky, a 37-year-old lawyer for Hermitage Capital Management, once Russia's biggest investment fund, died on Nov. 16 in a Moscow prison hospital while awaiting trial for tax evasion. His relatives say he was denied medical treatment.

Human rights activists have said Russian authorities subjected Magnitsky to conditions amounting to torture in a failed bid to force him to testify in their favour in a battle with Hermitage over tax fraud allegations.

In October 2008, Magnitsky implicated two Interior Ministry officers in an alleged $230 million fraud involving the illegal seizure of Hermitage's Russian investment holding companies to set up fake tax refunds.

Malmstrom's statement said Magnitsky had "courageously testified" about the fraud.

"Despite the high-profile nature of the case, no murder investigation has been initiated, nor have any prosecutions been brought against these interior ministry officers for the theft of $230 million," it said.

The EU statement came ahead of an EU-Russia summit on Monday in Rostov-on-Don, Russia, at which Russia is keen to make progress on relaxation of visa regulations for its citizens wanting to visit the European Union.

Malmstrom stressed before travelling to Russia that the EU linked visa liberalisation to respect for human rights.

Last month, a U.S. senator call on Washington to cancel U.S. visa privileges for 60 Russian officials and others over Magnitsky's death.

(Reporting by David Brunnstrom; editing by Ralph Boulton)