"We have four of those [Zika cases] in 2016 so we are seeing cases coming back," PHE’s head of Gastrointestinal, Emerging and Zoonotic Infections Department Dr. Dilys Morgan told The UK Parliament select science and technology committee.
Morgan said all four cases were detected among those who traveled abroad, but warned that more Zika cases are "likely" in the United Kingdom.
Overall, the United Kingdom has seen six cases over the past three years, Morgan added.
The Zika outbreak originated in Brazil last spring, spread across Latin America, then to the United States, Europe and China early in 2016.
The World Health Organization (WHO) declared the outbreak a public health emergency on February, saying the Zika virus was "spreading explosively."
The Zika virus is transmitted by mosquitos active in daytime. It does not cause serious complications in adults, but is suspected of leading to severe brain defects and microcephaly cases in newborns.