US Senator Robert Menendez 'faces corruption charge'
The US justice department is preparing to bring criminal corruption charges against Democratic Senator Robert Menendez, US media reports say.
The politician from New Jersey is alleged to have used his office to promote the interests of a Democratic donor, in exchange for gifts.
Attorney General Eric Holder has reportedly given prosecutors permission to proceed with charges.
Senator Menendez has labelled the probe a smear campaign.
"I am not going anywhere," he said on Friday at a press conference in New Jersey.
"Let me very clear, very clear. I have always conducted myself appropriately and in accordance with the law."
An official announcement from prosecutors is expected in the coming weeks.
Dominican Republic trips
Sen Menendez is one of the highest-ranking Hispanic members of Congress and a former chairman of the Senate's foreign relations committee.
The BBC's Nada Tawfik says Senator Menendez is also one of President Barack Obama's strongest opponents on lifting the embargo on Cuba and negotiating with Iran over its nuclear programme,
For the past two years, he has faced an investigation into his relationship with friend and donor Dr Salomon Melgen, following accusations that he paid for underage prostitutes for the senator in the Dominican Republic.
Senator Menendez vehemently disputed the claims and the allegations were eventually withdrawn.
FBI officials continued to look into the ties between the two men and the scrutiny shifted to whether Senator Menendez had traded gifts for official duties.
On Friday, Sen Menendez said that he had known Dr Melgen for more than two decades and that their families had been "real friends".
According to CNN, the government's case focuses in part on plane trips Sen Menendez took in 2010 to the Dominican Republic as a guest of Dr Melgen.
Prosecutors also are examining what role the senator played in helping Dr Melgen secure a deal to sell port screening equipment to the government of the Dominican Republic.