Dallas ? A $44.9 million chateau-style mansion that may have been the most expensive home in Dallas was destroyed in a fire early Thursday just weeks before completion.

It took 300 firefighters eight hours to put out the blaze at Chateau Du Triomphe, situated along Dallas’ Billionaire Row down the road from Ross Perot’s house.

The house in the exclusive Preston Hollow neighborhood had been under construction since 1995 and had never been occupied. At the time of the fire, it was listed for sale with Christie’s auction house.

The cause of the blaze was under investigation.

The main house, a 43,000-square-foot, three-story structure, had an Olympic-size swimming pool and custom marble tubs carved in Italy.

According to state records, the property was owned by Texas Treasure Fields Inc. But the identity of its owners was not immediately clear.