Contraband seized by customs officers has gone missing from a secure depot close to Coventry airport.
The Customs depot is close to Coventry airport
Police have been called in to search for the goods which disappeared from the HM Revenue and Customs (HMRC) store before last weekend.
A HMRC spokesman refused to comment on claims drugs, firearms and passports may have gone missing.
He said officials were cooperating with Warwickshire police. "We are taking this matter very seriously," he added.
HMRC said security had been stepped up and investigations were continuing, but did not reveal when or how the items disappeared.
The customs spokesman said: "We can confirm that a small number of items are missing from one of our offices in the Coventry area.
"We cannot comment further on this matter, it's the subject of an ongoing investigation."
The depot is used to store thousands of pounds worth of contraband seized by customs officers after it enters the UK illegally in parcels shipped from abroad.
The shadow chancellor George Osborne called the loss "a very serious security breach by her Majesty's Revenue and Customs".
He added: "Of course it comes after the fact that they have lost the discs containing the details of every family in the country and this points to systemic failure in one of the biggest departments of government."