Several financial moves by legal entities controlled by Donald Trump and Jared Kushner between 2016 and 2017 triggered suspicious activity alerts inside Deutsche Bank, a major lender to the Trump family, according to a report in the New York Times.

The newspaper said it had been in touch with five existing or former Deutsche Bank employees, one of whom spoke on the record. They said they had been alerted to possible illicit activity when they were working in the team responsible for combating money laundering, and had recommended the federal government be notified.

Suspicious activity reports were prepared for filing with the US treasury for investigation as possible federal financial crimes. According to the Times, bank executives overruled the employees and did not alert the government.

The Times pointed out that the “red flags raised by employees do not necessarily mean the transactions were improper”.

Deutsche Bank has become a lightning rod for concerns about the financial propriety of real-estate deals pursued by Trump and his wider family, including his son-in-law Kushner, a key adviser, before and after the billionaire entered the White House. Trump is thought to have borrowed at least $2bn from the German bank – some $300m still outstanding.

In the House of Representatives, Democrats have been drilling into the link between the Trump Organization and Deutsche Bank. Last month two committees – financial services and intelligence – issued subpoenas for documents from the bank.

Trump counter-attacked by launching a lawsuit against Deutsche Bank in an attempt to stop it complying with the subpoenas. The lawsuit claimed the demand for documents amounted to harassment of the president and his family.

The former Deutsche Bank employee who spoke openly to the Times, Tammy McFadden, said she prepared suspicious activity reports and recommended they be sent to federal watchdogs.

“You present them with everything, and you give them a recommendation, and nothing happens,” she said.

Donald Trump passes his adviser and son-in-law Jared Kushner at the White House in 2017. Photograph: Kevin Lamarque/Reuters

McFadden told the Times she was fired after raising concerns about transactions, among them contacts between Kushner Companies and Russian individuals in the summer of 2016. Deutsche Bank has been fined for laundering billions of dollars for Russians.

Deutsche Bank told the Times “the suggestion that anyone was reassigned or fired in an effort to quash concerns relating to any client is categorically false”. The bank also told the Times it had increased its scrutiny of potential money laundering.

The Trump Organization said it had “no knowledge of any ‘flagged’ transactions with Deutsche Bank”.

Kushner Companies said any allegation involving its links with Deutsche and money laundering were “totally false”.

Among Trump's claims of a “fake news” conspiracy against him, the Times is a prominent target. In a statement to Reuters about the Deutsche Bank report, a Kushner Companies spokeswoman sounded a familiar note, saying the paper “tries to create scandalous stories which are totally false when they run out of things to write about”.