Justin Bieber has cancelled an upcoming show in Portugal "due to unforeseen circumstances".

The 'Baby' singer was due to perform at the Pavilhão Atlântico venue in Lisbon on March 11 and March 12, but has called off the latter performance.

Announcing the cancellation on the venue's website, the statement read: "Due to unforeseen circumstances, Justin Bieber was forced to cancel the second performance in Portugal, March 12. The Canadian singer is eager to play for the Portuguese fans on March 11."

Those who have tickets are being offered refunds.

The Canadian superstar was plagued by a number of disasters in the London as he embarked on the UK leg of his tour last week.

The singer's behaviour was labelled "disgusting" when he failed to turn up on time to his first show at the O2 Arena in the capital.

Bieber was also involved in a foul-mouthed scuffle with a cameraman earlier this week - another of many negative stories to hit the headlines while the star was in the UK. Watch Justin Bieber's 'Right Here' lyric video below: