Kruis will have the advantage of being an uknown quantity

The 30-year-old has agreed a one-year contract and is the club's first signing under the Kolpak regulations.

"We are delighted to have Deon aboard to give us experience and stability," said Director of Cricket David Byas.

Kruis has taken 292 first-class wickets at an average of 29 during his career and spent last summer playing club cricket for Blackpool.

But his arrival marks a major change of policy by Yorkshire, who were among the clubs most critical of Kolpak signings.

"It is up to the counties to take a collective stand and to make sure such players are not admitted into the English game," chairman Robin Smith told the Yorkshire Post last summer.

Yorkshire's hand was forced by the winter departure of Steve Kirby to Gloucestershire and Matthew Hoggard's likely involvement with England throughout the summer.

Chris Silverwood is the only established new ball bowler on the staff with Scot John Blain struggling to establish himself at Headingley last summer and David Lucas, who has joined the club from Notts, yet to make his debut.

"I am delighted to be joining a county of Yorkshire's stature," said Kruis.

"I feel I could play a part in restoring former glories but I am encouraged to be helping the young Yorkshire talent that is emerging.

The Kolpak ruling, made by the European Court, allows cricketers from South Africa, Zimbabwe and the West Indies to sidestep the overseas quota of two players per side.