AceShowbiz - Mel Gibson has stepped up his ongoing legal dispute with a building company, accusing the firm of billing him for "hundreds of thousands of dollars" of "unnecessary" work. The "Braveheart" star and his estranged wife Robyn were sued by executives at Ramage Construction in September after allegedly failing to pay around $12,000 for work completed in 2000 on homes on Gibson's Malibu, California estate.

The building chiefs demanded the former couple pay up and threatened to place the properties in foreclosure. Gibson has hit back at the claims by filing his own legal papers, claiming the company carried out work which was "excessive" and billed the star for the extra jobs.

In the documents, filed at Los Angeles County Superior Court and obtained by TMZ.com, the actor claims Ramage chiefs conned him by billing for "hundreds of thousands - if not millions - of dollars of work... that was unnecessary or excessive". He also alleges the workers botched the installation of elevators, sprinkler systems and electrical wiring.

Gibson criticizes the company for going public with their September lawsuit, with his lawyers branding it "an attempt to intimidate and embarrass Mr. Gibson... into paying them even more unwarranted sums".