Hillary Clinton’s overlap of private and political activities was once again in the spotlight on Thursday after a Wall Street Journal report that since Clinton helped broker a settlement in a legal tax case against UBS while she was secretary of state, the Swiss bank has increased its financial support and involvement in Clinton Foundation projects.

In February 2009, the IRS sued UBS and demanded that it disclose the names of 52,000 possible American tax evaders with secret Swiss bank accounts. In the months that followed – thanks to involvement of Clinton as secretary of state and Swiss lawmakers – a legal settlement was negotiated. On 19 August 2009, it was announced that UBS would pay no fine and would provide the IRS with information about 4,450 accounts within a year.

Since the deal was struck, disclosures by the foundation and the bank show the donations by UBS to the Clinton Foundation growing “from less than $60,000 through 2008 to a cumulative total of about $600,000 by the end of 2014”, according to the Wall Street Journal.

The bank also teamed up with the foundation on the Clinton Economic Opportunity Initiative, creating a pilot entrepreneur program through which UBS offered $32m in loans to businesses, the newspaper reported. Other UBS donations to the Clinton Foundation include a $350,000 donation from June 2011 and a $100,000 donation for a charity golf tournament.

Additionally, UBS paid more than $1.5m in speaking fees to Bill Clinton between 2001 and 2014, the newspaper reported.

On Monday, UBS posted a bigger-than-expected jump in second-quarter net profits. Photograph: Arnd Wiegmann/Reuters

A UBS spokeswoman told the Journal that any insinuation of a connection between the legal case and the Clinton Foundation “is ludicrous and without merit”.

“Any suggestions that [Clinton] was driven by anything but what’s in America’s best interest would be false. Period,” said a Clinton campaign spokesman. He referred UBS-related questions to the State Department, which told the Journal that the bank was a topic of “serious discussion, among other issues” in bilateral talks with the Swiss.

Clinton’s involvement in the UBS settlement is no secret. A Reuters analysis of the settlement negotiations published in April 2010 showed that Clinton was involved at several points in the process.

According to the report, the US State Department was grateful to the Swiss for their support in places like Cuba and Iran and for “helping to broker a deal that normalized relations between Turkey and Armenia”. As such, then-Swiss foreign minister Micheline Calmy-Rey was able to connect with Clinton over the phone and meet her face to face three times before the deal was struck in August.

The Wall Street Journal claims that Clinton’s involvement was “more extensive than previously reported”. Using cables published by WikiLeaks and interviewing people involved, the Journal reported that prior to the deal being struck, the Swiss assisted in a release of a US journalist jailed in Iran, told the US that Swiss-based energy-consulting company Colenco would shut down its Iran operations and expressed willingness to accept some low-risk Guantánamo detainees.