Senior White House advisor Jared Kushner is being pushed to divest himself of ownership in a real estate company he cofounded after he 'failed to disclose' his ownership in the burgeoning online investment platform.

Kushner, the president's son-in-law, 'failed to disclose' his ownership interest in Cadre, an on-line real-estate company, according to a 15-page letter to the Office of Government Ethics Thursday by Citizens for Responsibility and Ethics in Washington.

Kushner co-founded the company along with his brother, Joshua Kushner, and Ryan Williams, who met Josh at Harvard.

The firm sought to raise $65 million in venture capital last month, The Real Deal reported, which would give it a valuation of $800 million.

Senior White House advisor Jared Kushner is being pushed to divest himself of ownership in a real estate company he cofounded but failed to list on a disclosure form filed with the government

Kushner's camp has not revealed his precise ownership stake, although his attorney, Jamie Gorelick has said he had reduced his stake to less than 25 percent. If his stake were 24 per cent, it would be about $190 million.

Filers are required to report assets worth more than $1,000 or that bring in more than $200 in income.

'These cannot be written off as minor oversights,' according to a release from CREW that accompanied its letter.

Kushner completed his forms after lengthy conversations with the government intended to resolve potential conflicts of interest proposed by his substantial technology and financial holdings.

The letter states that Kushner 'very likely failed to disclose his ownership interest in documents connected with his request for a certificate of divestiture,' which lets federal employees defer capital gains taxes when they sell assets to comply with conflict of interest rules.

It argues that in that case, the office would have approved his request based on 'incomplete information' – and that Kushner should be forced to forced to 'sell his interests.'

Kushner is being pushed to divest from Cadre, a firm he cofounded along with his brother, Joshua Kushner, pictured with Karlie Kloss attending the Cleveland Cavaliers vs New York Knicks game at Madison Square Garden on March 26, 2016 in New York City

CEO of Cadre Ryan Williams speaks onstage during TechCrunch Disrupt NY 2017

Cadre allows investors to buy into commercial real estate deals using an online platform. Investors reportedly include Republican boogeyman George Soros, venture capitalist Peter Thiel, and a Goldman Sachs fund.

A Kushner spokesman declined to comment on the latest development, but attorney Jamie Gorelick responded to a Wall Street Journal story in May, saying Kushner's stake would be described in a revised version of his disclosure form.

She said it was 'very normal' for such forms to be revised and that Kushner's lawyers prepared it for him.

Kushner's revised form could be completed in a matter of weeks.

Gorelick said Kushner had previously discussed his ownership in Cadre with OGE officials, had 'resigned from Cadre’s board, assigned his voting rights and reduced his ownership share.'

UNFORGETTABLE: Cadre allows investors to buy into real estate deals online

The firm trumpets its values on its web page

COUNT ME IN: Financier and philanthropist George Soros is reportedly among the firm's investors

Venture capitalist Peter Thiel, pictured between Apple CEO Tim Cook and President Trump, is an investor

The Journal also revealed that Kushner had failed to disclose business loans totaling $1 billion.

Gorelick said Kushner's ownership of Cadre was housed within BFPS Ventures LLC, which is identified on the form. Her statement that it would be included in a revised form appears to confirm that it was left off the first one.

'As part of this restructuring, Mr. Kushner's interest in Cadre was transferred to BFPS Ventures, LLC, which appears on line 20 of the draft of the 278e form released March 31, 2017,' according to her statement. 'Additional details regarding this asset appear on the current non-public draft of his 278e form, which will be disclosed following OGE certification. The interest in Cadre was added before we were contacted by the Wall Street Journal.'

The Kushner spokesman declined to provide Kushner's precise ownership stake, or say why it got left off the forms the first time.

It isn't clear what effect if any CREW's letter will have on the agency. According to its website, 'The U.S. Office of Government Ethics (OGE) does not handle complaints of misconduct, nor does OGE have investigative or prosecutorial authority. OGE's mission is one of prevention.'

SUNLIGHT: Kushner's attorney says he is preparing a revised disclosure form, which would seem to suggest there were omissions on the first one

The letter calls Kushner's failure of disclosure 'deeply troubling' because Cadre 'appears to be one of his largest investments, and his co-investors include some of the most prominent investors in the technology and financial services industries.'

It also raises questions, without fully leveling the accusation, of whether it was withheld as part of an 'intentional effort to hide an interest that was relevant to whether Mr. Kushner's technology and electronic commerce assets would be eligible for a certificate of divestiture in the first instance.'

The watchdog group asked OGE to determine whether Kushner 'violated any laws or rules.'

Kushner is currently traveling with President Trump in Europe, along with his wife, Ivanka Trump.