A consulting firm with ties to Hillary Clinton is refusing to answer questions from a Senate panel looking into whether the firm exerted undue influence on Clinton's State Department.

Teneo Strategies, a firm founded by two officials with deep connections to the Clintons, declined to respond to most of the Senate Judiciary Committee's questions in an Oct. 23 letter to the panel, according to a Reuters report.

Some of those questions included uncertainties about a previously undisclosed 2012 meeting at Teneo's office between Cheryl Mills, Clinton's chief of staff, and employees at the company.

Teneo became a focus of congressional investigators after they learned Huma Abedin, Clinton's deputy chief of staff at the State Department and currently her campaign's vice chair, had obtained a "special government employee" status that allowed her to collect paychecks from the State Department, the Clinton Foundation and Teneo.

Sen. Charles Grassley, chairman of the Judiciary Committee, has pointed to an unpublished inspector general inquiry that suggested Abedin leveraged her government position to benefit Teneo and the Clinton Foundation, which would constitute a major conflict of interest if true.

Abedin's legal team has forcefully denied all such allegations.

But neither Abedin nor Teneo have publicly addressed the questions surrounding the arrangement, nor have they settled controversy over whether the consulting firm had business before the State Department.

In the letter to the Senate Judiciary Committee, Declan Kelly, Teneo's CEO, characterized his company's Washington work as an insignificant portion of its overall business.

Kelly co-founded Teneo in 2011 after departing Clinton's State Department, where he served as a special envoy to Northern Ireland. Doug Band, a longtime Clinton aide, also founded the venture.

Critics have accused Band of exploiting his connections to the Clintons to enrich himself through Teneo.

The letter from the Senate panel to Teneo posed 16 questions about its ties to the State Department and alluded to emails between Clinton's agency staff and the firm's employees that may raise questions about whether Teneo's business ever intersected with the State Department.