Ex-NFL star Shawne Merriman is being taken to federal court for fraud by a company claiming he owes more than $2.5 million … TMZ has learned.

According to court docs, obtained by TMZ, a company called ARI Agent LLC claims Shawne took millions of dollars in financing but has not repaid a single cent. The investment firm says the former NFL star borrowed the money for his company, Lights Out XF, which is focused on mixed martial arts and entertainment.

ARI says this is no “routine default or simple contract dispute, but a deliberate, coordinated, multi-step scheme by Merriman to commit fraud, coercion, misrepresentation, and obstruction — all designed to avoid repayment and accountability.”

The company said Shawne ran the company into the ground, which resulted in no reliable revenue and an inability to meet basic obligations.

ARI insists these were not “isolated acts” but part of “a pattern of misconduct designed to extract capital, conceal risk, and avoid repayment.”

The lender also claims Shawne sent threatening messages — including voicemails that going after him would “open a can of worms” — in an effort to deter ARI from seeking to recover the money. The company is now suing, seeking the unpaid balance and additional damages.