The 28-year-old has penned a four-and-a-half year deal at the west London club, with the Hoops reported have paid £12.5m to secure the defender’s signature.
“This is an unbelievable signing,” Redknapp told QPR’s website.
“Tony Fernandes deserves a lot of credit for this one – he has worked so hard on bringing him in.
“I was speaking with him a month ago and he asked me who I would want to sign if Ryan Nelsen left, he asked me to give him a couple of names.
“I said to him, ‘Well, these aren’t possible to get but if you’re asking me who I’d have, I’ll give you a couple of players.’ One of them was Chris Samba.
“The next thing I know he’s telling me that he’s working on bringing him in! It’s amazing.
“Chris is just what we need. He’s a monster. Great in the air, quick, a leader, strong, fantastic in both boxes, hard as nails. He’s a proper centre-half.”
Samba has scored three goals in 23 appearances for the Russian top-flight side this season after joining Anzhi from struggling Rovers in February 2012.
The Congo international, who will wear the number five shirt, admitted that he is delighted to complete a return to the Premier League after a 11-month absence.
“I’m delighted to be back in the Premier League. It’s the best league in the world to play football,” said Samba. “I’ve been linked with the club for a long time.
“With Harry here though, he is really passionate and he wants to do something with the club. Unfortunately things haven’t gone the way the club would have wanted so far this season but there’s still a lot of time and I’m sure we can get out of it.”
Samba, capped 26 times by Congo, is also confident that QPR can move clear of the relegation zone and remain in the Premier League.
“I know what is going on with the project here. There is a very important fan base, I’ve played at Loftus Road before and it’s fantastic,” he added.
“The club is ambitious and I’m sure it’s a good challenge for me. If I can be a part of it I will be very proud, it will be a great achievement for me.
“I wouldn’t be here if I didn’t believe we could get out of trouble.”
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