Kevin Kennedy says Bill Tarmey and Liz Dawn cheated on Coronation Street by writing their lines down on props.
The former soap star claimed the late cobbles legends - who played Jack and Vera Duckworth - struggled to cope with the hectic filming schedules.
To make sure they knew their lines, they would scribble sections of the scripts onto objects on set to give themselves a helping hand.
Kevin - who played Curly Watts from 1983 until 2003 - appeared on the Kevin Clifton Show podcast and said: "Bill and Liz did not have the technique of learning lines so they wrote little notes everywhere.
"I went to reach for the cornflakes and Bill was like, 'Eh son, don't touch that. There are lines on it.'
Bill and Liz did not have the technique of learning lines so they wrote little notes everywhere.
"Then I went to get the milk and Liz went, 'Hey, leave that alone. It has got my lines on it.' They made that work and were brilliant."
Liz sadly died after a lengthy period of ill health in 2017, and at the time Kevin said he could "only smile" when he remembers her.
He previously told This Morning: "I can only smile when I think of Liz, it's very sad but what she's left behind her is very valuable."
Kevin doesn't think Liz really knew how good she was on screen and always doubted her talent.
He added: "She was a lot cleverer than people thought she was.
"And, in regards, to acting, she didn't think she was very good. She was very humble in that respect.
"She took me under her wing and looked after me.
"I used to live very close to her and she was always inviting the younger cast round to her house and we used to go there and have a laugh.
"She was brilliant and made sure we were all OK. She was the one you could go to if you were having problems."
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