Dee ihe ọzọ maka paragraf a - N'egwuregwu Olimpik nke afọ 2012 e mere na London, Agnel nwetara ọla atọ: ọlaedo abụọ na ọlaọcha otu. N'ihe omume mbụ ya, Agnel gbara mbọ na-abịa n'azụ na 4 × 100 mita freestyle relay iji merie ọla edo na Amaury Leveaux, Fabien Gilot, na Clément Lefert. N'ịbanye n'ime mmiri na 0.55 sekọnd, Agnel nwere ike belata nke ahụ na 0.30 sekọnd na akara 350 mita. N'ime mita 50 ikpeazụ, Agnel gara n'ihu onye America bụ Ryan Lochte na France meriri na oge 3:09:93 na oge United States nke 3:10:38. Agnel gbara ọsọ kachasị ọsọ n'ogige ahụ dum na oge nke 46.74, naanị onye gafere sekọnd 47. N'echi ya, Agnel nwetara nrite ọlaedo ya nke abụọ na 200 mita freestyle na oge nke 1: 43.14, nke kachasị ọsọ na akụkọ ntolite French na 1.79 sekọnd n'ihu ndị meriri ọla ọcha Sun Yang na Park Tae-hwan. N'ikpeazụ, Agnel na-eduga site na mmalite ruo na njedebe, na-edekọ oge nke 50.64 na mita 100 mbụ na 52.50 na mita 100 ikpeazụ. Oge ya nke 25.98 maka mita 50 ikpeazụ bụ nke kachasị ọsọ n'ọhịa. Agnel nwetara ihe nrite ikpeazụ ya, ọlaọcha, na 4 × 200 mita freestyle relay n'azụ United States na Amaury Leveaux, Grégory Mallet, na Clément Lefert. O nwere oge kachasị ọsọ nke ubi na njedebe na oge nke 1:43.24 dị ka ụkwụ arịlịka. N'asọmpi ikpeazụ ya, 100 mita freestyle
Agnel gbara nke anọ n'oge kachasị mma nke 47.84, 0.04 nke abụọ na-abụghị nke ọla. Ndị European Swimming Federation kpọrọ Agnel nwoke Europe na-egwu mmiri nke afọ 2012.