Plenty of Premiership clubs have been revealing deals in recent weeks, with the likes of Leicester and Wasps strengthening for the 2016/17 campaign and beyond.
That has prompted Saints fans to wonder whether their club will be adding more fresh faces in the coming weeks.
And when asked that question, Hewitt said: “We’re still very much in the market for next season, trying to recruit players in certain positions.
“It’s ongoing and we’ll make those announcements in due course.”
Saints have already secured a marquee signing of their own, with France star Louis Picamoles heading to the Gardens this summer.
The capture of the Toulouse No.8, which was announced back in November, is a sizeable coup for Northampton.
And Hewitt said: “We’re excited that we’ve got Louis Picamoles coming here. He’s a major world-class player coming in.
“That was fantastic because there was a lot of pressure on that with other clubs.
“We’re delighted to have got that done and he’s someone with more than 50 caps for France. It’s great to have a French player coming into England at that level.
“That gives us the big ball carrier that we’ve been looking for.”