Saiz was questioned by Spanish police but later released

Saiz was questioned and released by Spanish police on Wednesday in what has been described as Spain's biggest anti-doping investigation.

And Liberty Seguros announced in a statement on Thursday it had made its decision in the wake of his detention.

Saiz has been told he must be available to appear before a judge when required.

A statement from Liberty Seguros said: "As sponsors, we have always wanted to promote a culture of fair play and zero tolerance with respect to doping.

"In November 2005 after the suspension of a rider (Roberto Heras) for doping we made our contract one of the most rigorous with regard to this subject.

"The implications and consequences of the detention of Manolo Saiz are highly worrying - they damage our name and the name of cycling.

"We have cancelled our agreement with the owners of the team (Active Bay) and will respect outstanding financial obligations."

Spain's Civil Guard on Wednesday gave few details of the investigation in a statement on Wednesday.

It said: "Five people have been detained as suspects for crimes against public health.

"The Guard have raided a number of addresses and found a large quantity of medical supplies such as anabolic steroids etc, laboratory equipment for use in blood transfusions, and more than 100 frozen packs of blood."

Doping is not a criminal offence in Spain, so the investigation centres on public health issues.

Such offences carry prison sentences of between six months and three years.

This is the second time the Liberty team has been rocked by controversy.