"Ihor Myronovych Yeremeyev, 47, has died in hospital in Zurich, Switzerland," she said.
Funeral details will be announced later.
Media reports about Yeremeyev's death appeared on August 12.
He sustained a head injury falling from a horse in Lutsk, Ukraine, on July 26, 2015. He was transported to a hospital abroad on July 28, 2015.
Yeremeyev was a co-owner of Continuum, a group of companies that owns the WOG gas filling chain. He was also head of the supervisory board of PJSC Bank of Investment and Savings (BIS Bank).
He was elected to Ukraine's Parliament in 2002, 2012 and 2014.