Big Dig officials said Monday they may need another $12 million for repair work after last month's fatal ceiling panel collapse, and warned the price tag could climb higher if more trouble spots are discovered.

The Turnpike Authority board of directors is expected to vote Wednesday on the request $12 million from Big Dig project manager Michael Lewis. The board previously approved $3 million for the first round of repairs.

The request does not include the cost of retrofitting about 3,300 steel brackets holding up ceiling panels in the closed ramps and tunnels. Last week investigators discovered the brackets, which need to support three times the weight of the panels, were designed only to support about twice the panel weight.

Former Turnpike board member Jordan Levy said taxpayers shouldn't have to foot the bill for repairs. He said the Turnpike should go after Big Dig project manager Bechtel/Parsons Brinckerhoff and other contractors who worked on the project.

"We paid for it once. We shouldn't have to pay for it again," Levy said.

A spokesman for Bechtel/Parsons Brinckerhoff said the company stands behind its work.

"Since investigators are still gathering tens of thousands of documents it's premature to determine fault, but we will always be here to stand behind our work," said company spokesman Andy Paven.

Several Big Dig tunnels and ramps have been closed to traffic since 12 tons of concrete ceiling panels fell from the I-90 connector onto a vehicle carrying Milena Del Valle, crushing her to death.

The initial price tag for the Big Dig, which replaced a highway network with underground tunnels in and around downtown Boston, was $2.6 billion and it was supposed to be completed in seven years.

Instead, it took nearly 15 years and the cost ballooned to $14.6 billion, making it the most expensive highway project in the nation's history.