E-mails have been sent to Channel 4 containing threats against Celebrity Big Brother housemates, police said tonight.
Hertfordshire Police would not say if the e-mails were related to the furore surrounding alleged racist comments made by several housemates about Bollywood star Shilpa Shetty.
A spokesman said: "We can confirm Hertfordshire Constabulary have been made aware of two e-mails that have been received by the television studios that contain unspecified threats against a number of the housemates. Police are currently looking in to the e-mails."
Hertfordshire Police also confirmed they have received a complaint about racist behaviour in the house. In total more than 10,000 complaints have been made to industry watchdog Ofcom and Channel 4.
A police spokesman said: "We can confirm Hertfordshire Constabulary received one telephone call complaining about alleged racist behaviour.
"The caller was referred to Ofcom who will be dealing with all complaints of this nature."
The news came as the chief executive of Carphone Warehouse said he is reviewing the firm's sponsorship of Celebrity Big Brother because of alleged racism in the house.
Charles Dunstone told The Times he was in talks with bosses at Channel 4 due to concerns about the treatment of Shetty.
Complaints began to flood in after Jade Goody, her mother Jackiey Budden, Jack Tweed, Danielle Lloyd and Jo O'Meara allegedly began bullying the Indian actress.
In one outburst Lloyd asked Shetty: "Do you get stubble?" and in another Budden, who constantly called her "the Indian" asked: "Do you live in a house or a shack?"
Mr Dunstone said: "We are talking to Channel 4. The sponsorship is constantly under review. Clearly we are against racism.
"Most people understand that the person who has their name associated with the programme does not necessarily condone the content."
He added that the responsibility for the content of Big Brother lay with the maker of the programme.
The Carphone Warehouse began sponsoring Big Brother in 2004. The current deal is thought to be worth £3m (€4.5m) a year.
Mr Dunstone's comments are the latest blow for the show which has already seen three celebrities walk out and suffered disappointing viewing figures.
Now bookmakers William Hill have cut the odds of Celebrity Big Brother not lasting its scheduled run from 20/1 to 5/2 as pressure builds on the programme.
William Hill spokesman Rupert Adams said: "Channel 4 could make their decision for any number of reasons, and despite the fact that Big Brother is one of their success stories, we will not be offering such generous odds in the future."
No Big Brother spokesman was available for comment. But a spokesman previously defended producers' decision to show the offending remarks.
He said: "The social interactions of the group are part of the Big Brother story and viewers have a right to see these portrayed accurately.
"This is balanced with our duty not to broadcast material that may cause unjustifiable offence."
Big Brother rules state that anyone guilty of racist abuse in the house can be evicted. However in 2002 when one contestant told a joke including the word "paki" he was only given a reprimand.