[bigbrotherisback2009]

An average of 5.1million viewers tuned in to the Big Brother 10 launch show last night, according to unofficial overnight figures.

4.8million people (a 22.1% share of the audience) tuned in to see this year’s contestants enter the Big Brother house on Channel 4, whilst a further 293,000 (1.9%) watched it on timeshift service Channel 4+1.

The show’s peak audience came at 10.15pm, when 5.3million were watching, and it attracted three million more viewers than the Channel 4’s slot average for 2009 so far (1.8million, 8.1%).

Whilst it rated worse than last year’s launch show, which drew an average of 5.4million, it was the most watched programme in its timeslot last night.

A Taggart repeat on ITV1 drew the second highest audience of 3.3million (14.8%). BBC One was third, with 3million (13.6%) watching their documentary Calendar Girls: Ten Years On, whilst an episode of The Mentalist on Five was the fourth most watched with 2.5million viewers (11.1%).

A Channel 4 spokeswoman said: “Last night’s launch was the second highest audience so far this year on Channel 4. We are very pleased with the viewing figures.”

Meanwhile, the debut episode of Big Brother’s Big Mouth, which aired straight after the launch, pulled in 580,000 viewers to digital channel E4.

Official ratings, which take other factors in to account including those who recorded the show, will be released later.