BERLIN — Germany's foreign intelligence chief Ernst Uhrlau Tuesday admitted that blueprints for his service's new headquarters in Berlin had been stolen, but played down the danger posed by the loss.

The missing blueprints are those of a parking area and of a "power generating centre", not those "at the heart" of BND intelligence-gathering offices currently under construction and due for completion in 2014, Uhrlau told reporters.

There was no reason to amend building plans, he added.

He did not know when the blueprints, kept at the building site, vanished, saying only that "at some point it appears something went missing".

The documents were labelled confidential, but not top secret, he added.

The government had announced on Monday that the BND was investigating the loss.

The BND has its headquarters in Pullach, on the outskirts of the southern city of Munich. Following reunification it was decided however to move them to Berlin and building started there in 2006.

Construction on the site in the former communist east of the city is expected to cost 1.6 billion euros ($2.2 billion).

The BND, one of Germany's three secret services, is responsible for gathering intelligence abroad.