Thousands of Network Nine viewers calling a Who Wants to be a Multi-Millionaire prize hotline on Monday night unwittingly voted for Australian Idol contestant Carl Riseley.

The Nine Network competition offered viewers the chance to win $10,000 by either calling a 1902 number or text messaging their answer.

Host Eddie McGuire was forced to apologise on air after callers were directed Network Ten’s Australian Idol.

A spokesperson for Belong, which works with 1900 numbers, confirmed some callers received an Australian Idol voting message for a short period.

The spokesperson said the result was audited prior to the announcement of the Monday night eliminee from Australian Idol.

Each week a contestant is voted off the singing competition styled show by the public.

Carl Riseley the contestant who benefited from the vote, a former bugler with the Royal Australian Navy, was not eliminated from the show.

Instead fellow Idol Marty Simpson a 21-year-old surfer from the NSW Central Coast was removed from the show.