One of America’s leading Christian universities has been hit by lurid allegations of sexual and financial misconduct, the latest scandal to engulf the world of televangelism.

The president of Oral Roberts University, which sits in the heart of America’s Bible Belt in Oklahoma, is accused of using donors’ money to buy his wife expensive cars, fund private jet trips for his daughter, remodel his home and maintain a stable of horses for his children.

The wife of Richard Roberts is also accused of sending hundreds of text messages to “underage males” who had been provided with university-issued mobile phones, and spending tens of thousands of dollars on clothes with university funds.

Another allegation, contained in a lawsuit filed by three former professors, is that a long-time maintenance man on campus was dismissed so that an underage male friend of Lindsay Roberts, known as the university’s “First Lady”, could have his job.

The 5,300-student university was founded 44 years ago by Oral Roberts, the first evangelist to lead large televised revivals in which worshippers claimed to be miraculously healed. Today it is one of the most successful evangelical empires in the US, receiving tens of millions of dollars in contributions a year. In 2005 the university reported nearly $76 million (£37 million) in revenue to the tax authorities.

Students must sign a pledge that they will live by the university’s honour code, which bans lying, swearing, smoking, drinking, gambling and a range of sexual acts, including homo-sexuality. Oral Roberts, now 89, handed the day-to-day running of the university to his son Richard in 1993.

The three professors claim that they were dismissed after reporting the university’s allegedly illegal involvement in a political campaign.

According to the lawsuit, Richard Roberts insisted that a professor use his students to help a local county commissioners’ unsuccessful bid to become Mayor of Tulsa, a breach of state and federal law because of the university’s charitable status.

The professors claim that they were dismissed after they turned over to the board of regents a copy of a report detailing moral and financial abuses by Mr Roberts and his family. The document had been prepared by Mr Roberts’s sister-in-law. A student found it when repairing her laptop computer and gave a copy of it to one of the professors, according to the lawsuit.

It detailed dozens of alleged instances of misconduct. Mrs Roberts was given a red Mercedes convertible and sports utility vehicle at donors’ expense. The Roberts’s home, according to the document, has been refurbished 11 times in 14 years. Mrs Roberts spent more than $39,000 at a Chico’s clothing shop in less than a year, and had other accounts in California and Texas. According to the document, she also repeatedly said: “As long as I wear it once on TV, we can charge it off”.

The university jet was allegedly used to take one daughter and several friends on a trip to Florida and the Bahamas. The $29,411 tour was billed to the ministry as an “evangelistic function of the president.”

Mrs Roberts frequently had mobile phone bills of more than $800 a month, with hundreds of text messages sent between 1am and 3am to “underage males . . . provided phones at university expense”. The Roberts are also accused of summoning university employees to their home to do their daughters’ homework.

Mr Roberts said at a chapel service: “This lawsuit is about intimidation, blackmail and extortion. We live in a litigious society. Anyone can get mad and file a lawsuit against another person whether they have a legitimate case or not.”

Screen saviours

Jim Bakker Sentenced in 1989 to 5 years in jail for embezzling $158 million in church money, including $265,000 to pay off his mistress

Jimmy Swaggart Caught with a prostitute, and forced to resign his ministry in 1988

Ted Haggard In 2005, married preacher admitted to buying methamphetamines and contacting gay prostitutes

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