England captain Alastair Cook believes that Stuart Broad is back to his best after the seamer took 6-52 in the second Test draw with New Zealand.

The 26-year-old paceman, who has been hindered by a recurring heel injury this winter, stormed through the Kiwi middle order as England established a mammoth first-innings lead in Wellington.

Wet weather denied England victory, which leaves the series deadlocked ahead of the deciding Test in Auckland this week, but Cook was able to take positives in Broad's improved form, if not the result.

"He's certainly back to his best. He ran in as well as I've seen him for a while," said Cook.

"It was great to see him delivering again like that. I think that's his seventh 'five-for'. I think he's fully confident now with his heel, and it's great to have a senior bowler back."

Broad has taken 187 wickets at an average of 31.45 in his 54 England Test matches.