Amy Winehouse got married in a secret ceremony in May

The 23-year-old, who was nominated for the Mercury Music Prize, was due to appear as a support act in Dusseldorf and Hamburg.

The cancelled sets are the latest in a string of gigs the singer has pulled citing exhaustion or ill health.

A spokesman for the star declined to comment over a Sunday newspaper's claim she was treated for a drugs overdose.

Classic rock band, The Answer, will replace her as the opening act for tonight's concert in Dusseldorf.

'Exhaustion'

British rock group Starsailor will play at Wednesday's gig in Hamburg.

Winehouse is still scheduled to perform at Staffordshire and Chelmsford's V Festivals at the weekend.

In the past few weeks she has pulled out of the T in the Park festival - also citing "exhaustion" - and Liverpool's Summer Pops event.

Despite cancelling a string of concerts recently Winehouse has been frequently photographed in pubs when she had been expected to appear on stage.

The singer, who won best song at the Mojo awards in June, has put her habit of cancellations down to being a perfectionist.

Last week she received three nominations at the MTV Video Music Awards, including Female Artist of the Year.