New documents have confirmed that Family First Senator Bob Day effectively gave $1.47 million to his political party a year after taking a sizable dividend from his loss-making home-building empire.

Key points: Lent $1.47 million to his political party

Lent $1.47 million to his political party The fact that repayments were not required only just revealed

The fact that repayments were not required only just revealed Senator Day to resign from the Senate after the collapse of his companies

Senator Day this week announced he will resign from the Senate, after the Home Australia group of companies was placed into liquidation.

In an update to its 2013-14 donation disclosures, filed with the Electoral Commission, Family First has confirmed Senator Day forgave a loan to the party totalling $1,471,000.

The line of credit had appeared in the political party's previous year's return, but the fact that repayment had been excused was not clear until Friday's update.

The records show Senator Day also made separate donations of $484,000 to the party in 2013-14 and $73, 200 in 2014-15, putting his total donations to the party in excess of $2 million.

In 2012-13, Senator Day and his business partner reaped dividends totalling $2.67 million from the then loss-making Home Australia business.

The company's finances were already under pressure at that stage. Financial reports show the company's net liabilities exceeded more than $30 million.

Auditors later warned that figure presented a "material uncertainty which may cast significant doubt about the consolidated entity's ability to continue as a going concern".

But the extent of Senator Day's business troubles were not necessarily clear to the public.

Home Australia's 2012-13 and 2013-14 audited financial reports were not signed off until October 2015, and were not filed with the corporate regulator ASIC until August 18 this year.

Senator Day was officially re-elected to the 12th and final spot on the South Australian Senate ticket on August 2.