The tax man has slapped former Quebec construction mogul Tony Accurso with more than 900 charges and is seeking nearly $8.5 million.

Revenue Quebec accuses Accurso's former companies — Simard-Beaudry, Louisbourg Construction and Marton Construction — of filing false declarations and invoices while claiming false tax credits and refunds.

Those are just some of the companies that belonged to Accurso, who ran a massive construction empire.

Last fall, Revenue Quebec raided the offices of Accurso's former companies, saying they were looking for evidence of tax fraud and would lay charges if warranted.

The charges stem from the period between June 1, 2005 and March 31, 2010. A spokesman for Revenue Quebec says the charges announced today are under the penal, not criminal, system and the maximum punishment is two years' imprisonment.

In addition, Accurso and his right-hand man, Frank Minicucci, are accused of filing false returns for the same period.

"It was a scheme that was elaborate and well-planned," said Revenue Quebec spokesman Stéphane Dion.

Accurso withdrew from his businesses amid a mounting pile of scandals and legal woes. Now added to that mountain of troubles are new charges against him and his firms — 470 of which directly name him as an individual or company administrator.

"Prison sentences will also be sought for the presumed cases of tax fraud in the construction industry," said a statement Wednesday from the revenue agency and Quebec's anti-corruption unit.

The statement also said the $8.5 million amount was only the minimum fine.

A large part of Accurso's construction empire was sold to a consortium earlier this year, several months after he annouced he was quitting the construction business.

This is the latest in a string of legal problems plaguing the businesses and Accurso personally.

In 2010, Construction Louisbourg Ltd. and Simard-Beaudry Construction Inc. were ordered to pay a combined $8 million in fines and back taxes after pleading guilty to federal charges of tax evasion.

In April 2011, Accurso was charged with fraud, conspiracy, influence peddling, breach of trust and two counts of defrauding the government in connection with an investigation by Quebec's anti-corruption unit that found that public officials allegedly benefitting from gifts and money given in exchange for favourable decisions and privileged information.

In August 2012, Accurso was arrested on charges linked to a multimillion-dollar federal tax-evasion conspiracy, and was released by police the same day.

The RCMP arrested Accurso along with another Quebec construction magnate, Francesco Bruno, and former Canada Revenue Agency auditor Adriano Furgiuele on the same charges, as part of the still-unwinding saga of corruption in the province's construction sector that touches all levels of government.

His name also has come up in the testimony of several witnesses before Quebec's Charbonneau commission.

Accurso was not arrested Wednesday but has been ordered to appear before a judge on Sept. 25.

with files from CBC News